I have just come back from helping out my Dad with his car. He fitted a new air filter and cleaned the top of the flap which the air travels down into the engine through as it was black. I was there with him and he gave the area a spray with intake cleaner and gave it a wipe out. Would pressing on the flap cause it to fail?

 

Now the engine runs roughly and as soon as it has warmed up just chugs and won't respond to the accelerator at all. The check engine light is on as well as the traction control light.

 

When the engine is cold the car runs but as soon as it warms up it will only move along at idle revs.

 

The flap is not opening up as the engine warms.

 

Just wondering if the flap could now be faulty after the cleaning or is there a way of doing a reset that may help?

 

Thanks for any help as the car is now unusable. 

Any chance you've knocked and damaged one of the wires going to the throttle body while you were cleaning the butterfly valve?

...or unplugged it and lost the adaptation.

Cheers. I was fitting the panel filter while I asked my dad to clean up the intake. I gave him the cleaning spray and cloth but wasn't watching exactly. Nothing looked disturbed at all and the only thing he said he did was to push the cloth in to wipe. If the flap is manualy operated is it delicate enough to break? I just tried the car again and its the same. Lumpy idle and misfire until revving and then gets worse as the engine warms. Is it worth ordering a new throttle body? Do they fail like this?

 

I have spent years fettling Estelles and Rapids but bit lost with all the electronics here.

1 minute ago, Mr105LUX said:

If the flap is manualy operated is it delicate enough to break?

Very much doubt it, having taken one apart.

2 minutes ago, Mr105LUX said:

Is it worth ordering a new throttle body? Do they fail like this?

 

Very much doubt it,...

 

Check the wiring at the cable entry of the loom plug, the wires are thin and fragile-looking.

Moving the throttle flap doesn't usually cause a problem. Seems like something's been disturbed.

Thanks. Ill take a fresh look in the morning. 

For such a weird and unexpected problem I would be guessing something reducing airflow. I would try returning the car to how it was. Carefully retrace your steps. Pull the engine cover off. Remove the new air filter. Put the old air filter back. Double check for cleaning rags left in various passages of the engine cover/intake. See how it runs. Could just be a faulty new filter? But throttle body disturbance remains favourite.

Edited 26 May, 20188 yr by LB123

25 minutes ago, LB123 said:

For such a weird and unexpected problem I would be guessing something reducing airflow. I would try returning the car to how it was. Carefully retrace your steps. Pull the engine cover off. Remove the new air filter. Put the old air filter back. Double check for cleaning rags left in various passages of the engine cover/intake. See how it runs. Could just be a faulty new filter? But throttle body disturbance remains favourite.

 

Is this how ritual magic works? 

I did this once when building up an engine. All the ports had been blocked to prevent dirt getting into my skimmed ported head. Only three of the rags had been removed. Not ritual magic. Just a senior moment. Getting to be more of a problem as time goes on. I do find if I encounter odd/unexpected changes after I have been working on an engine it's usually my error.

Right. Update time.

 

All checked and nothing was loose or distubed. This time I removed the throttle without unplugging it and cleaned underneath. It was pretty caked up so some scraping and cleaning soon had it spotless. All back together and tried again. Just the same but I noted the following. 

 

With engine started from cold it runs sort of ok but misfires unless being revved. Throttle flap moves.

With engine warmed up it no longer responds to the throttle (engine stays at a lumpy 1250 rpm) and throttle flap does not move. Even when you floor the throttle the engine only pulses. When turning off the ignition the engine takes a moment to stop like its running rich.

 

I may just call AA homestart but does this issue sound familiar to anyone?

 

Lastly what are the symptoms of a failed throttle unit? 

 

Thanks for any input. 

9 minutes ago, Mr105LUX said:

may just call AA homestart

May as well if you have that cover. Ask for and write down the numbers of any fault codes the AA person reads.

Still sounds like a wiring problem to me, but fault codes will help narrow down the possibilities. Worth checking all the fuses that relate to engine management too, can't remember if there is one in the drive by wire circuit.

21 minutes ago, Mr105LUX said:

This time I removed the throttle without unplugging it...

 

Yeah, so about that TB adaptation routine that I mentioned earlier...

 

If you don't adapt it it simply won't run. Please ask for more information if this is a foreign language I'm speaking.

Cheers. I worded it badly - I meant that instead of cleaning it in situ I unbolted it to clean the underside properly. Its never been unplugged. 

I'm pleased to say that it's now all fixed. Called AA homestart and the Polish engineer was soon on the case.

 

Throttle body was fine and all electronic connections and the fault was the brake servo hose had popped off behind the engine. It must have been loosening for a while and the removing of the engine cover finished the job.

 

Now it has a jubilee clip and the engine is running better than ever.

 

The hose coming off of the brake system was the reason that the traction control light was lit.

I hope that jubilee clip keeps it in placed and sealed okay, from my memory when I replaced that servo pipe on a 2002 Polo 1.4 1.6 75PS due to the one way valve passing in both directions, I found that the pipe stub is buried inside a tube, VW original fit used a slim clamp there and the new hose came fitted with a modified one so that it was just forced into place.

 

What I am saying is, for long term fault free running, I reckon that fitting a jubilee clip is not a very good idea as you end up with the jubilee clip position being just out beyond the pipe stub so not working as intended.

Thanks for feeding back with the outcome. 

On 27/05/2018 at 00:54, LB123 said:

I do find if I encounter odd/unexpected changes after I have been working on an engine it's usually my error.

I quote myself.

Car still running fine. Many of the recent niggles have been resolved too. Namely poor throttle response and pinking on acceleration. The hose must have been just resting there but sucking in air. Good job it never popped off on a long motorway journey I recently undertook. 

 

Thanks again for the help.